This invention relates to shoes, and, more particularly, to a shoe which can be used as a roller skate and then converted for use as a walking shoe.
Roller skates, and more recently in-line skates, have been commercially available for some time. While useful for skating, footwear of this type are not suitable to walk in, particularly over surfaces which are rough or uneven. As a result, unless one skates over a smooth surface and returns to where he or she started, it is necessary to carry a pair of walking shoes, sneakers or the like for use after the skating is completed.
This problem has been addressed in the past by the provision of a unit typically comprising an adjustable length frame formed in the general shape of a footprint having rollers mounted at the front end and the back end. The frame is affixed to the outsole of a shoe, such as a sneaker, usually by clamps, straps or a combination of the two. Although this arrangement has the advantage of allowing a sneaker or other article of footwear to convert to a roller skate, frames of this type have proven to be unsuitable except for use by small children. At higher speeds, and with increased side-to-side movement imposed by the skating of older children or adults, it has been found that the frame becomes unstable and tends to disengage from the shoe.
More recently, alternative designs have been proposed for a shoe which can be converted from a roller skate to a walking shoe and visa versa. One approach has been to form a shoe with a relatively thick outsole having a recess in both the heel area and the arch area of the shoe. One or more rollers are mounted within each of the recesses, which are movable between a retracted position and an extended position. In the retracted position, the rollers are completely contained within the recesses and the shoe can be used as a walking shoe. With the rollers in the extended position, the shoe functions as a roller skate. See, for example, U.S. Pat. No. 6,328,318 to Hsu; U.S. Pat. No. 6,308,964 to Chang; U.S. Pat. No. 6,247,708 to Hsu; U.S. Pat. No. 6,120,039 to Clementi and others.
As noted above, convertible shoes with retractable rollers require a comparatively thick outsole so that the recesses may be formed to receive the rollers. This adds expense and detracts from the comfort of the shoe when used as a walking shoe instead of a roller skate. Additionally, relatively complicated mechanisms are required to extend and retract the rollers with respect to the recesses which adds cost, both in terms of parts and labor for assembly.
Another approach utilized to convert a shoe for use as both a walking shoe and roller skate is disclosed, for example in U.S. Pat. No. 6,354,609 to Chen et al and U.S. Pat. No. 5,511,824 to Kim. Shoes of this type generally comprise a shoe upper connected to an outsole which is formed with an internal bore both in the heel area and arch area of the shoe. A rod or shaft is inserted through each of the bores such that its ends protrude from the sides of the outsole. Each rod mounts a first wheel at one end and a second wheel at the opposite end to convert the shoe for use as a roller skate. The mounting structure for the wheels on at least one side of the outsole is such that it can be disengaged to permit the wheels and rod to be removed, allowing the shoe to function as a walking shoe.
Although simpler in construction and cheaper to manufacture and assemble than the convertible shoes with extendable and retractable rollers, shoes of the type described in the Chen and Kim patents noted above have limitations. In the U.S. Pat. No. 5,511,824 Kim patent, a relatively complex bushing and pushpin arrangement is employed to secure a wheel to one end of the rod or shaft. A simpler, less expensive design is shown in the Chen Patent U.S. Pat. No. 6,354,609, which includes a pin and pivot member combination to secure the wheels on one side of the rod or shaft, but this construction can come apart and allow the wheel to disengage the shaft.
It is therefore among the objectives of this invention to provide a shoe which can be converted for use as a walking shoe and a roller skate which is simple in construction, inexpensive to manufacture and assemble and which provides protection against disengagement of the wheels when used as a roller skate.
These objectives are accomplished in a shoe which is convertible between a walking shoe and a roller skate comprising a shoe upper connected to an outsole formed with an internal bore at both the heel area and arch area, each of which receive a hollow sleeve carrying a rod whose opposite ends protrude from the sides of the outsole. A first end of each rod mounts a wheel which is retained thereon by a fixed end cap, and the opposite, second end of each rod has opposed, radially outwardly extending locking pins which are received within bores formed in a locking cap. The locking cap is effective to retain a second wheel on the second end of each rod.
In the presently preferred embodiment, the second end of each of the rods is formed with opposed bores which align with one another. Locking pins are inserted within the interior of the second end of each rod, in alignment with the opposed bores, and are connected to one another by a spring. In order to assemble a wheel on the second end of a rod, the locking pins are initially moved to a retracted position in which the spring is compressed and both locking pins are located entirely within the interior of the second end of the rod. With the locking pins remaining in the retracted position, a wheel is placed over the second end of the rod, and then a locking cap is located over the bores in the second end. Preferably, the locking cap is formed with a number of circumferentially spaced, radially extending bores, each dimensioned to receive one of the pins. When the locking cap is in alignment with the locking pins, the locking pins move to the extended position under the influence of the spring and each protrude into one of the radial bores of the locking cap to maintain it in place on the rod.
One advantage of the wheel locking arrangement of this invention is that a xe2x80x9cback-upxe2x80x9d structure is provided to resist disengagement of the wheel from the second end of the rod. The wheel is formed with a through bore having a diameter slightly greater than that of the rod. In turn, the diameter of the locking cap is greater than that of the through bore so that it engages the hub or side of the wheel to prevent it from sliding off of the rod. The locking cap therefore comprises the primary means of retaining the wheel on the second end of the rod. Preferably, the length dimension of the two locking pins, measured from the tip of one pin to the tip of the other in their extended position, is also greater than the diameter of the through bore of the wheel. Consequently, even if the locking cap should become disengaged from the locking pins and removed from the second end of the rod, the ends of the locking pins would engage the side or hub of the wheel to retain it in place until the locking cap could be replaced. The locking pins therefore provide a back-up or secondary retention means for the wheel.